278 THE EFFECT OF MANURES. 



localities, and not to bo generally applicable to meadow land 

 which is nioAvn for hay. The hay crop is a great exhauster of 

 the mineral constituents of the soil ; and these owing to the high 

 price of the salts of potash, cannot, M'ith profit, bo fully restored 

 in artificial nnmures. The return of the mineral constituents is 

 better accomplished by means of farmyard manure, night soil, 

 and the like. 



''The grasses jiroper appear to be the most strikingly inde- 

 pendent of any artificial supply of carbon. Tlie hay crop is 

 more exhaustive of potash than wheat or barley. 



"A i)redominance of mineral elements in the fertilizers in- 

 creased the proportion of the culms of grasses, while a predom- 

 inance of ammoniacal salts increased the proportion of leaves. 



*" Those manures which much increased the produce of hay, 

 at the same time very much increased its proportion of gramina- 

 ceous jdants. 



** The total miscellaneous herbage (chiefly Avceds) were the 

 most numerous in kind and nearly in the greatest proportion on 

 the unmanured land, viz: IG per cent., while on the manured 

 plat they decreased to 2 per cent." 



"An artificial manure containing a sufficiency of mineral and 

 nitrogenous constituents affected some of the grasses as follows : 



LoJinm jxii't'fun' proportionally considerably increased. 



IfoJciis J(tnafiis i)roportionally largely increased. 



ArrJiriKifJu'i'idH avcnaceum proportionally largely diminished. 



Anthoxanihum odorafum proportionally largely diminished. 



Agi'Qstix vuhjaris proportionally very much diminished. 



Briza media proportionally very much diminished. 



Cyiwsnrns crisfafus proportionally very much diminished. 



Daciylis glomcraia proportionally very much increased. 



Poa pratetisis proportionally very much dimiuished. 



Bromus mollis proportionally reduced. 



Arena pratensis proportionally increased. 



